The present invention relates to a method for joining a tube element and a core element together.
The method of the invention can be applied particularly in the manufacturing of the suspension bars for electrodes, particularly for permanent cathodes, used in the electrolysis of metals. The structure of the suspension bar of permanent cathodes and the joining of the plate part of the permanent cathode to the suspension bar is made problematic by the fact that in order to conduct a high electric power to the plate part, the suspension bar must contain some highly electroconductive material, such as copper, because acid-resistant steel has poor electroconductivity, and consequently it cannot be the sole material of the suspension bar. In the patent publication WO 00/17419, there are introduced alternative methods for manufacturing the suspension bar of a permanent cathode. These methods are typically complicated and/or require special devices. In arrangements manufactured according to the methods of the prior art, the electroconductive properties of the joint have not always been maintained in a satisfactory way, especially in the corroding conditions that prevail in the electrolytic processes of metals.
The object of the present invention is to realize a novel method for joining the tube element and the core element together. Another object of the invention is to realize a method that is economical as regards to manufacturing technology and well suited to the targets of usage for manufacturing the suspension bar of an electrode, particularly a permanent cathode.
The arrangement according to the invention is characterized by what is set forth in the appended claims.
The arrangement according to the invention has several remarkable advantages. By means of the method of the invention, there is achieved a good, electroconductive joint between the jacket element with a lower electroconductivity and the core element with a high electroconductivity. The method is easily implemented without special devices. The method is suited to be applied in the manufacturing of products of very different sizes and, on the other hand, in the manufacturing of varying quantities of products.